Leonard Brand

A high-risk method for studying psychosocial antecedents of chronic pain : the prospective investigation of herpes zoster

Although patients with chronic pain are often psychologically distressed, it has been difficult to determine whether this distress is an antecedent of chronic pain or whether it is caused by the experience of living with chronic pain. The aim of this investigation was to develop a method that would allow individuals who are at risk for the development of chronic pain to be studied before their pain has become chronic. Patients with acute herpes zoster were assessed with demographic, medical, pain, and psychosocial measures. Pain was assessed in follow-up interviews at 6 weeks and 3, 5, 8, and 12 months after these initial assessments. There were no significant differences between patients who developed short-term herpes zoster pain and patients who did not develop short-term pain for any of the measures at the initial assessment, except for one measure of pain intensity. Patients who developed chronic herpes zoster pain, however, had significantly greater pain intensity, higher state and trait anxiety, greater depression, lower life satisfaction, and greater disease conviction at the initial assessment than patients who did not develop chronic pain. In discriminant analyses, disease conviction, pain intensity, and state anxiety each made a unique contribution to discriminating patients who did and who did not develop chronic pain. This study demonstrates the feasibility of investigating psychosocial antecedents of the development of chronic pain by prospectively examining the longitudinal course of herpes zoster.

Unraveling the effects of compensation, litigation, and employment on treatment response in chronic pain.

&NA; Although it has often been suggested that chronic pain patients who are receiving workmens compensation or who have litigation pending are less likely to benefit from treatment, the results of outcome studies of this question conducted by various pain clinics have been inconsistent. We hypothesized that poorer outcome in such patients may be related to the fact that they are less likely to be working and that the inconsistent results in the literature may therefore be explained by variability among studies in the percentages of patients who are receiving compensation (or who have litigation pending) who are also working. We examined the relationships among compensation, litigation, employment, and short‐ and long‐term treatment response in a series of 454 chronic pain patients. Compensation benefits and employment status both predicted poorer short‐term outcome in univariate analyses; however, when employment and compensation were jointly used to predict outcome in multiple regression analyses, only employment was significant. In additional analyses, only employment significantly predicted long‐term outcome, whereas compensation and litigation did not. Our results suggest that it would be valuable to redirect attention away from the deleterious effects of the ‘compensation neurosis’ and toward the roles of activity and employment in the treatment and rehabilitation of chronic pain patients.

Predicting treatment response in depressed and non-depressed chronic pain patients

&NA; Although it has often been observed that chronic pain and depression are associated, there have been few systematic comparisons of chronic pain patients with and without depression. In the study reported in this article, depressed and non‐depressed chronic pain patients were found to be quite similar with respect to demographic, pain‐related, and treatment response variables. The primary aim of the study, however, was to examine the hypothesis that treatment response in these two groups of patients would be predicted by different patterns of variables. In non‐depressed patients, beneficial response to treatment was related to a greater number of treatment visits, not receiving workmens compensation, fewer previous types of treatment, and low back pain. As predicted, a different pattern of predictors of treatment response was found for the depressed patients, who were more likely to benefit when they were employed at the beginning of treatment and when their pain was of shorter duration. These results suggest that activity and active involvement in treatment are particularly important with chronic pain patients who are depressed. In addition, they suggest that the best prediction of treatment response in future research on chronic pain patients may be achieved by dividing patients into groups based on psychological characteristics.

The influence of urinary pH on the plasma half-life of pseudoephedrine in man and dog and a sensitive assay for its determination in human plasma.

A sensitive method has been developed which allows estimation of pseudoephedrine in plasma at drug concentrations as low as 0.05 fLg per milliliter, making possible, for the first time, the measurement of pseudoephedrine in human plasma. In 3 normal volunteers, the plasma ty, of pseudoephedrine was 5.2,7.6, and 8.0 hours, respectively. When urinary pR was decreased by the administration of NR,Cl, the plasma ty, of pseudoephedrine decreased markedly. In contrast, when urinary pR was increased by the ingestion of NaRCOs, the plasma ty, of pseudoephedrine increased.

Recovery after procaine-induced seizures in dogs

Abstract 1. 1. Generalized convulsions can be produced in most dogs by the i.v. administration of procaine hydrochloride 100 mg/kg. 2. 2. In paralyzed mechanically ventilated dogs this dose of procaine produces repetitive EEG seizure discharges similar in timing to the generalized motor convulsions seen in unparalyzed dogs. 3. 3. Maintenance of good ventilation is a major factor in recovery after such seizures regardless of their duration. Room air is adequate for this purpose. 4. 4. Both generalized convulsions in unparalyzed dogs and repetitive EEG seizure discharges in paralyzed dogs can be terminated by the injection of thiopental 100 mg i.v. 5. 5. In paired experiments in the same dog, recovery times were similar whether seizures were suppressed promptly with thiopental or allowed to terminate spontaneously, provided good ventilation was maintained.